Chapter 14 - Enterprise Software

Enterprise software is a computer software used to satisfy the needs of an organization rather than individual users. such organizations would include businesses , school , interest-based user groups , clubs , charities , or governments. Enterprise software is an intergral of a information system. 

Also, Enterprise computing involves the use of computers in networks, such as LANs and WAN, or a series of interconnected networks that encompass a variety of different operating systems, protocols, and network architectures .

Types of enterprises include:

1. Retail
2. Manufacturing
3. Service
4. Wholesale
5. Government
6. Educational     
7. Transportation

The common categories in an enterprise are:

1.   Executive management.
2.   Middle management.
3.   Operational management.
4.   Non-management employess.

Most traditional enterprises are organized in a hierarchical manner In an enterprise, users typically fall into one of four categories: 

1.  Executive Management
2. Middle Management
3. Operational Management
4. Nonmanagement Employees

Enterprise information is the information gathered in the ongoing operations of an enterprise-sized organization

1.        Business intelligence
2.        Business process management 
3.        Business process automation

Managers coordinate resources by performing four activities :

1. Planning  
2. Organizing
3. Leading
4. Controlling 

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 Information Systems in the Enterprise

An information system is a set of hardware, software, data, people, and procedures that work together to produce information

Functional units within an enterprise might include:

1. Enterprise
2. Accounting and Finance
3. Human Resources
4. Engineering or Product Development
5. Manufacturing
6. Marketing
7. Sales
8. Distribution
9. Customer Service
10. Technology

• Accounting software manages everyday transactions
• Billing software helps the company reconcile purchases with customer payments
• Financial software helps managers budget, forecast, and analyze
• A human resources information system (HRIS) manages one or more human resources functions.
• Employee relationship management systems manage communication between employees and the business.
• Computer-aided design (CAD) uses a computer and special software to aid in engineering, drafting, and design.
• Computer-aided engineering (CAE) uses computers to test product designs.
• Computer-aided manufacturing (CAM) is the use of computers to control production equipment.
• Computer-integrated manufacturing (CIM) uses computers to integrate the many different operations of the manufacturing process.
• Material Requirements Planning (MRP) uses software to help monitor and control processes related to production.
• Manufacturing Resource Planning II (MRP II) is an extension of MRP and also includes software that helps in scheduling.
• A quality control system helps an organization maintain or improve the quality of its products or services.
• A marketing information system serves as a central repository for the tasks of a marketing department.
• Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.

 

• Distribution systems perform the following functions:

1. Provide forecasting for inventory control
2. Manage and track shipping of products
3. Provide information and analysis on inventory in a warehouse

• Customer interaction management (CIM) software manages the day-to-day interactions with customers.

• The information technology (IT) department makes technology decisions for the enterprise.

1. Whether to build or buy new information systems
2. When a computer or information system has outlived its useful life

• Web site management programs collect data designed to help organizations make informed decisions regarding their Web presence

• General purpose information systems generally fall into one of five categories.

1. Office Information System
2. Transaction Processing System
3. Management Information System
4. Decision Support System
5. Expert System

• Batch processing vs. online transaction processing.
• A Sample Expert System In Windows 7 Help and Support

1. A user enters the nature of the problem.
2. Select a suggested solution from the list presented by the expert system.
3. Expert system displays details about the solution and additional options.
4. Expert system displays detailed steps when requested.

• Integrated Information Systems

1. Customer relationship management manages information about customers, interactions with customers, past purchases, and interests
2. Enterprise resource planning provides centralized, integrated software to help manage and coordinate ongoing activities
3. Content management systems are information systems that combine databases, software, and procedures.

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  Enterprise-Wide Technologies and Methodologies

• Some technologies used in enterprises include:

1. Portals - A portal is a collection of links, content, and services presented on a Web page that are interesting for a particular job function.
2. Data warehouses - A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
3. Electronic data interchange - EDI is a set of standards that controls the transfer of business data and information among computers both within and among enterprises.
4. Extranets - An extranet is the portion of a company’s network that allows customers or suppliers of a company to access parts of an enterprise’s intranet.
5. Web services - Web services allow businesses to create products and B2B interactions over the Internet. In a service-oriented architecture, information systems provide services to other information systems in a well-defined manner over a network.
6. Document management systems - A document management system (DMS) allows for storage and management of a company’s documents
7. Stored in a repository
8. Workflow - A workflow is a defined process that identifies the specific set of steps involved in completing a particular project or business process.
9. Workflow application
10. Virtual private networks - A virtual private network (VPN) provides mobile users, vendors, and customers with a secure connection to the company network server. Virtualization and Cloud Computing

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Virtualization is the practice of sharing or pooling computing resources.

1. Server virtualization - Provides the capability to divide a physical server logically into many virtual servers.
2. Storage virtualization - Provides the capability to create a single logical storage device from many physical storage devices.

• Cloud computing is an Internet service that provides computing needs to computer users.
• Grid computing combines many servers and/or personal computers on a network to act as one large computer.

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Enterprise Hardware

• Enterprise hardware allows large organizations to manage and store information and data using devices geared for:.

1. Heavy use
2. Maximum availability
3. Maximum efficiency

• RAID duplicates data and implements duplication in different ways.
• Network attached storage (NAS) is a server that provides storage to users and information systems attached to the network.
• A storage area network (SAN) is a high-speed network that provides storage to other servers to which it is attached.
• An enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company.
• Goal is to consolidate storage.
• A blade server packs a complete computer server on a single card (called a blade) rather than a system unit.
• The individual blades insert in a blade server chassis.
• A thin client is a small terminal-like computer that mostly relies on a server for data storage and processing.
• The processing for a thin client usually is done on a server.

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High Availability, Scalability, and Interoperability

• A high-availability system continues running and performing tasks for at least 99 percent of the time.
• May include hot-swapping and redundant components.
• When a component fails, another component takes over and the system continues to function.
• Scalability is a measure of how well computer hardware, software, or an information system can grow to meet increasing performance demands.
• Interoperability is the ability for an information system to share information with other information systems within an enterprise.

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Backup Procedures

• Continuous data protection provides automatic data backup whenever data is changed in an enterprise.
• A disaster recovery plan is a written plan describing the steps a company would take to restore computer operations in the event of a disaster.
• Contains four major components.

1. Emergency plan
2. Backup plan
3. Recovery plan
4. Test plan

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Chapter 13 - Computer Programs and Programming Language

A programming language is a special language programmers use to develop software programs, scripts, or other sets of instructions for computers to execute.Example application : C++ , JAVA .Computer program is a series of instructions that directs a computer to perform tasks. Created by a programmer using a programming language.

Low-level Language:  

1. Machine language is the first generation of programming languages, this language is only recognized by the computer.
2. Assembly language is the second generation of programming languages. use of symbolic instructions.
3. Source program contains the code to be converted to machine language.
4. Procedural language instructions that tell the computer what and how to do. 

Procedural Languages

In a procedural language, the programmer writes instructions that tell the computer what to accomplish and how to do it.
Third-generation language (3GL)

1. A compiler translates an entire program before executing it.
2. An interpreter converts and executes one code statement at a time.

The C programming language is used to write many of today’s programs.

COBOL (COmmon Business-Oriented Language) is designed for business applications, but easy to read because of the English-like statements.

Object-Oriented Programming Languages and Program Development Tools

An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects.
Other advantages include:

1. objects can be reused
2. programmers create applications faster
3. work well in a RAD environment
4. most program development tools are IDEs

Java is an object-oriented programming language developed by Sun Microsystems.
The Just-in-time (JIT) compiler converts the bytecode into machine-dependent code.
The Microsoft .NET Framework allows almost any type of program to run on the Internet or an internal business network, as well as computers and mobile devices.
 
Features include:

1. CLR (Common Language Runtime) 
2. Classes

-C++ is an extension of the C programming language.
-C# is based on C++ and was developed by Microsoft.
-F# combines the benefits of an object-oriented language with those of a functional language.
 
Visual Studio is Microsoft’s suite of program development tools:

1. Visual Basic is based on the BASIC programming language
2. Visual C++ is based on C++
3. Visual C# combines the programming elements of C++ with an easier, rapid-development environment]

A visual programming language is a language that uses a visual or graphical interface for creating all source code.

Borland’s Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.

PowerBuilder is a powerful program development RAD tool.
Best suited for Web-based, .NET, and large-scale enterprise object-oriented applications.

Other Programming Languages and Development Tools

A 4GL (fourth-generation language) is a nonprocedural language that enables users and programmers to access data in a database.
 
One popular 4GL is SQL
Classic programming languages include:

1. Ada
2. ALGOL
3. APL
4. BASIC
5. Forth
6. FORTRAN
7. HperTalk
8. LISP
9. Logo
10. Modula-2
11. Pascal
12. PILOT
13. PL/1
14. Prolog
15. RPG
16. Smalltalk

An application generator is a program that creates source code or machine code from a specification of the required functionality.

• Often bundled as part of a DBMS

A macro is a series of statements that instructs an application how to complete a task.

• You usually create the macro in one of two ways:
1. Record the macro with a macro recorder
2. Write the macro

Web Page Development
 
HTML is a special formatting language that programmers use to format documents for display on the Web.
 
XHTML is a markup language that allows Web sites to be displayed more easily on mobile devices.
 
XML allows Web developers to create customized tags and use predefined tags to display content appropriately on various devices.-WML is a subset of XML and is used to design pages for microbrowsers.

Two applications of XML are RSS 2.0 and ATOM.

Web browsers can execute short programs to add interactive elements to Web pages.

To send and receive information between your computer and a Web server, these programs use the CGI (common gateway interface).

Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages:

1. JavaScript
2. Perl
3. PHP
4. Rexx
5. Tcl
6. VBScript

Dynamic HTML  (DHTML) allows Web developers to include more graphical interest and interactivity.
Cascading style sheets (CSS) contain the formats for how a particular object should be displayed.

Ruby on Rails (RoR) provides technologies for developing object-oriented, database-driven Web sites.
Web 2.0 allows Web sites to provide a means for users to:

1. Share personal information
2. Allow users to modify Web site content
3. Have application software built into the site

Most Web 2.0 sites use APIs
-An API enables programmers to interact with an environment such as a Web site or operating system.
 
Web page authoring software can create sophisticated Web pages that include images, video, audio, animation, and other effects

1. Dreamweaver
2. Expression Web
3. Flash
4. SharePoint Designer

Multimedia Program Development

• Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.
• ToolBook
• Director
• Program development consists of a series of steps programmers use to build computer programs.

1st  - Analyze Requirements

To initiate program development, programmer:

1. Reviews the requirements
2. Meets with the systems analyst and users
3. Identifies input, processing, and output 

-IPO chart  

 
2nd  – Design Solution

Design a solution algorithm.
 

In structured design, the programmer typically begins with a general design and moves toward a more detailed design.
 

Programmers use a hierarchy chart to show program modules graphically.
 

With object-oriented (OO) design, the programmer packages the data and the program into a single object
-Encapsulation 

The sequence control structure shows one or more actions following each other in order.
 

The selection control structure tells the program which action to take, based on a certain condition.

1. If then else
2. Case

The repetition control structure enables a program to perform one or more actions repeatedly as long as a certain condition is met.

A program flowchart graphically shows the logic in a solution algorithm.

Flowcharting software makes it easy to modify and update flowcharts

1. SmartDraw
2. Visio

Pseudocode uses a condensed form of English to convey program logic.

UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development.

3rd – Validate Design

Check for logic errors using test data

1. Develop various sets of test data
2. Determine the expected result
3. Step through the algorithm
4. Compare the results
5. Repeat steps for each set of test data

4th  – Implement Design
 

Implementation of the design includes using a program development tool that assists the programmer by:

1. Generating or providing some or all code
2. Writing the code that translates the design into a computer program
3. Creating the user interface

Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.

   

5th – Test Solution

The goal of program testing is to ensure the program runs correctly and is error free.

1. Errors include syntax errors and logic errors.
2. Debugging the program involves removing the bugs.
3. A beta is a program that has most or all of its features and functionality implemented.  

6th – Document Solution

In documenting the solution, the programmer performs two activities:

1. Review the program code
2. Review all the documentation

Chapter 12 - Exploring Information System Development

System Development is the process of creating and maintaining information systems is called Systems Development or systems analysis and design. It involves all seven components of an information system. In addition to technical knowledge, it requires business knowledge and management skill.

Ongoing Activities

1. Project management
2. Feasibility assessment
3. Documentation
4. Data/information gathering

Planning

1. Review project requests
2. Prioritize project requests
3. Allocate resources
4. Form project development team 

Analysis

1. Conduct preliminary investigation
2. Perform detailed analysis activities:
3. Study current system
4. Determine user requirements
5. Recommend solution

 

 Design

1. Acquire hardware and software,if necessary
2. Develop details of system 

 

Implementation

1. Develop programs,if necessary
2. Install and test new necessry
3. Train users
4. Convert to new system

 Operation,Support,and Security

1. Perform maintenance activities
2. Monitor system performance
3. Assess system security 

System development should representatives from each department in which the proposed system will be used.

Project management is the process of planning, scheduling, and then controlling the activities during system development.

To plan and schedule a project efficiently, the project leader identifies:

1. Projectscope
2. Required activities
3. Time estimates for each activity
4. Cost estimates for each activity
5. Order of activities
6. Activities that can take place at the same time

Feasibility is a measure of how suitable the development of a system will be to the organization.

1. Operational feasibility
2. Schedule feasibility
3. Technical feasibility
4. Economic feasibility

Documentation is the collection and summarization of data and information.

A project notebook contains all documentation for a single project.

Users and IT professionals refer to existing documentation when working with and modifying current systems.

During system development,members of the project team gather data and information using several techniques.

1. Review documentation
2. Observe
3. Survey
4. Interview
5. JAD Sessions
6. Research

Who Initiates a System Development Project

1. A user may request a new or modified system.
2. Organisation wants to improve hardware, software or other technology.
3. Situations beyond an organization's control might require a change.
4. Management might mandate a change.
5. A user may request a new or modified information system using a request for system services or a project request.

Planning Phase
 
The planning phase for a project begins when the steering committee receives a project request
Four major activities are performed:

1. Review and approve the project requests
2. Prioritize the project requests
3. Allocate resources
4. Form a project development team 

Analysis Phase

 

The analysis phase consists of two major activities:

 

Conduct a preliminary investigation :

1. Determines and defines the exact nature of the problem or improvement.
2. Interview the user who submitted the request 

 

Perform detailed analysis :

1. Study how the current  system works
2. Determine the users' wants, needs, and requirement
3. Recommend a solution

 

Process modeling( structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs

1. Entity-relationship diagrams
2. Data flow diagrams
3. Project dictionary

An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system.
Entities are objects in the system that have data.
A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.

1. Data flow
2. Processes
3. Data stores
4. Sources

The project dictionary contains all the documentation and deliverables of a project.
Structured English is a style of writing that describes the steps in a process.
 

A decision table is a table that lists a variety of conditions and the actions that correspond to each condition.
 

A decision tree also shows conditions and actions, but it shows them graphically.
 

The  data dictionary stores the data item's name, description, and other details about each data item.
 

Object modeling combines the data with the processes that act on that data into a single unit, called an object.
 

UML (Unified Modeling Language) has been adopted as a standard ntation for object modelig and development
 

UML includes 13 different diagrams
Two diagrams include:

 

Case diagram:

1. A use case diagram graphically shows how actors (users) interact with the information system.
2. Diagrams are considered easy to understand.

Class diagram

1. A class diagram graphically shows classes and subclasses in a system.
2. Each class can have one or more subclasses.
3. Subclasses use inheritance methods and attributes of higher levels.

The system proposal assesses the feasibility of each alternative solution.
The steering committee discusses the system proposal and decides which alternative to pursue .

1. Packaged software
2. Custom software
3. Outsourcing

Design Phase

The design phase consists of two major activities
Acquire hardware and software
Develop all of the details of the new or modified information system
To acquire the necessary hardware and software:
Identify technical specifications

1. Use research techniques such as e-zines

Solicit vendor proposals

1. RFQ,RFP. or RFI is sent to potential vendors VARs

Test and evaluate vendor proposals

1. Various techniques are used to determine the best proposal

Make a decision

1. System analyst makes recommendation to steering committee

Next step to develop detailed design specifications 

Sometimes called a physical design:

1. Database design
2. Input and output design
3. Program design

Systems analyst typically develop two types of designs fr each input and output.
A prototype (proof of concept) is a working model of the proposed system

1. Prototypes have inadequate or missing documentation
2. Users tend to embrace the prototype as a final system
3. Should not eliminate or replace activities

Computer-aided software engineering (CASE) tools are designed to support one or more activities of system development.
CASE  tools sometimes contain the following tools:

1. Project repository
2. Graphically
3. Prototyping
4. Quality assurance
5. Code generator
6. Housekeeping

Many people should review the detailed design specifications.
An inspection is a formal review of any system development deliverable
A team examines the deliverables to identify errors.

Implementation Phase

The purpose of the implementation phase is to construct the new or modified system and then deliver it

1. Develop programs
2. Install and test the new system 
3. Train users
4. Convert to the new system

The program development life cycle follows these steps:

1. Analyze the requirements
2. Design the solution
3. Validate the design
4. Implement the design
5. Test the solution
6. Document the solution

Various tests should be performed on the new system
Unit test

• Verifies that each individual program or object works by itself

System test

• Verifies that all programs in an application work together properly

Integration test

• Verifies that an application work with other applications

Acceptance test

•  Checks the new system to ensure that it works with actual data

 

Training involves showing users exactly hoe they will use the new hardware and software in the system.

1. One on one sessions
2. Classroom style lectures
3. Web based training

 One or more f four conversion strategies can be used to change from the old system to the new system.

 

Operation, Support, and Security Phase

The purpose of the operation, support, and security phase is to provide ongoing assistance for an information system and its users after the system is implemented.

1. Perform maintenance activities
2. Monitor system performance
3. Assess system security

 A computer security plan should do the following:

1. Identify all information assets of an organization
2. Identify all security risks that may cause an information asset loss
3. For each risk, identify the safeguard that exist to detect, prevent, and recover from a loss

Chapter 11 - Manage Computing Securely , Safely and Ethically

Computer Security is the protection of computing systems and the data that they store or access.
Example:

1.To prevent theft of or damage to the hardware 
2.To prevent theft of or damage to the information
3.To prevent disruption of service 

Computer security risk- any event or action that could cause a loss of or damage to computer hardware, software, data, information and processing capability.
 
Cybercrime- an online or internet-based illegal act.
Example :

1. Hackers- hacker is any highly skilled computer expert capable of breaking into computer systems and networks using bugs and exploits.
2. Crackers- A person who exploits weaknesses in a computer or network
3. Script Kiddies- An unskilled individual who uses scripts or programs developed by others to attack computer systems and networks and deface websites.
4. Corporate Spies-A covert gaining competitor's information.
5. Unethical Employees- people who gain company's information and sell or provide to others company.
6. Cyberextortionists-crime involving attack or threat of attack with purpose to get money out of it.
7. Cyberterrorists-is the act of Internet terrorism in terrorist activities, including acts of deliberate, large-scale disruption of computer networks, especially of personal computers attached to the Internet, by the means of tools such as computer viruses.


An online security service is a Web site that evaluates your computer to check for Internet and e-mail vulnerabilities

Type of Internet and network attacks :

Computer Virus- Affects a computer negatively by altering the way the computer works.

Worm- Copies itself repeatedly using up resource and completely shut down the computer and network.

Trojan Horse- A malicious program that hides within or looks like a legitimate program.

Rootkit- A set of software tools that enable an unauthorized user to gain control of a computer system without being detected.


An infected computer has one or more of the following symptoms:

1.Operating system runs much slower than usual
2.Available memory is less than expected
3.File become corrupted
4.Screen displays unusual message or image
5.Music or unusual sound plays randomly
6.Existing programs and files disappear
7.Programs or files do not work properly
8.Unknown programs or files mystereriously appear
9.System properties change
10.Operating system does not start up
11.Operating system shuts down unexpectedly

Users can take several precautions to protect their home and work computers and mobile devices from these malicious infections.
A botnet is a group of compromised computers connected to a network.
A compromised computer is known as a zombie.

A denial of service attack (DoS attack) disrupts computer access to Internet services.
Distributed DoS (DDoS)

A back door is a program or set of instructions in a program that allow users to bypass security controls. 

Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate.

A firewall is hardware and/or software that protects a network's resources from intrusion. 

Intrusion detection software
1.Analyzes all network traffic
2.Assesses system vulnerabilities
3.Identifies any unauthorized intrusions
4.Notifies network administrators of suspicious behavior patterns or system breaches. 

Honeypot
Vulnerable computer that is set up to entice an intruder to break into it.

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 Unauthorized Access and Use

 

Unauthorized access is the use of a computer or network without permission. 

Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.

 

Organizations take several measures to help prevent unauthorized access and use

1.Acceptable use policy

2.Disable file and printer sharing

3.Firewalls

4.Intrusion detection software

 

Access controls define who can access a computer,when they can access it,and what actions they can take

1.Two-phase processes called identification and authentication

2.User name

3.Password

4.Passphrase

5.CAPTCHA

 

A possessed object is any item that you must carry to gain access to a computer or computer facility.

Often are used in combination with a personal identification number(PIN) 

 

A biometric devices authenticates a person's identify by  translating a personal characteristic into a digital code that is compared with a digital code in a computer. 

 

Digital forensics is the discovery,collection,and analysis of evidence found on computers an network.

 

Many areas use digital forensics

1.Law enforcement

2.Criminal prosecutors

3.Military intelligence

4.Insurance agencies

5.Information security department

6.Hardware Theft and Vandalism

 

Hardware theft is the act of stealing computer equipment.

Hardware vandalism is the act of defacing or destroying computer equipment.

 

To help reduce the of chances of theft,companies and schools use a variety of security measures

1.Physical access controls

2.Alarm systems

3.Cables to lock equipment

4.Real time location system

5.Passwords,possessed objects,and biometrics

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Software Theft

Software theft occurs when someone:

1.Steals software media
2.Intentionally erases programs

3.Illegally copies a program

4.Illegally registers and/or activates a program

 

A single-user license agreement typically contains the following conditions:

Permitted to：

1.Install the software on one computer

2.Make one copy of the software

3.Remove the software from your computer before giving it away or selling it

 

Not permitted to:

1.Install the software on a network

2.Give copies to friends or colleagues while continuing to use the software

3.Export the software

4.Rent or lease the software

 

Copying,loaning,borrowing,renting,or distributing software can be a violation of copyright law.

Some software requires product activation to function fully.

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Information Theft

 

Information theft occurs when someone steals personal or confidential information. 

Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.

 

Example of Public Key Encryption

1.The sender creates a document to be e-mailed to the receiver.

2.The sender uses the receiver's public key to encrypt a message.

3.The receiver uses his of her private key to decrypt the message.

4.The receiver can read or print the decrypted message.

 

A digital signature is an encrypted code that a person,Web site,or organization attaches to an electronic message to verify the identity of the sender.

-Often used to ensure that an impostor is not participating in an Internet transaction.

 

Web browsers and Web sites use encryption techniques.

 

Popular security techniques include.

1.Digital certificates

2.Transport Layer Security(TLS)

3.Secure HTTP

4.VPN

System Failure

 

A system failure is the prolonged malfunction of a computer.

 

A variety of factors can lead to system failure,including:

1.Aging hardware

2.Natural disasters

3.Electrical power problems

4.Noise,undervoltages,and overvoltages

 

Errors in computer programs

 

Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptable power supplies (UPS) . 

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Backing Up-The Ultimate Safeguard

 

A backup is a duplicate of a file,program,or disk that can be used if the original is lost,damaged, or destroyed.

to back up a file means to make a copy of it

Offsite backups are stored in a location separated from the computer site.

 

Two categories of backups:

1.Full backup

2.Selective backup

 

Three-generation backup policy

1.Grandparent

2.Parent

3.Child

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Wireless Security

 

Wireless access poses additional security risks

About 80 percent of wireless networks have no security protection.

 

War driving allows individuals to detect wireless network while driving a vehicle through the area.

In additional to using firewalls,some safeguards improve security of wireless networks:

1.A wireless access point should not broadcast an SSID.

2.Change the default SSID

3.Configure a WAP so that only certain devices can access it

4.Use WPA or WPA2 security standards

Ethics and Society

 

Computer ethics are the moral guidelines that govern the use of computers and information systems.

 

Information accuracy is a concern

Not all information on the Web is correct 

 

Intellectual property rights are the rights to which creators are entitled for their work.

 

An IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical.
 

Green computing involves reducing the electricity and environmental waste while using a computer. 

Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them.

 

Huge databases store data online.

 

It is important to safeguard your information

 

When you fill out a form,the merchant that receives the form usually enters it into a database.

 

Many companies today allow people to specify whether they want their personal information distributed.

 

A cookie is a small text file that a Web server stores on your computer.

 

Web sites use cookies for a variety of reasons:
1.Allow for personalization
2.Store user's passwords
3.Assist with online shopping
4.Track how often users visit a site
5.Target advertisements

E-mail filtering blocks e-mail messages from designated sources.
 

Anti-spam programs attempt remove spam before it reaches your inbox.
 

Phishing is a scam in which a perpetrator sends an official looking e-mail message that attempts to obtain your personal and financial information.

Spam is an unsolicited e-mail message or newsgroup posting.

Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing.
 

Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of trust and naivety.
 

Employee monitoring involves the use of computers to observe,record,and review an employee's use of a computer.
 

Content filtering is the process of restricting access to certain material on the Web.
Many businesses use content filtering.
Internet Content Rating Association(ICRA)
 

Web filtering software restricts access to specified Web sites.

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Chapter 10 - Managing a Database

A Database is a collection of information that is organized so that it can easily be accessed, managed, and updated. In one view, databases can be classified according to types of content: bibliographic, full-text, numeric, and images.

Database is a collection of data organized in a manner that allows accessing retrieval and use of that data.
Data  is a collection of unprocessed items such as text, number, images, video, and audio.
Information is where it processed data such as documents. images, video, and audio.
Database software,often called a database management system (DBMS), allows users to create a computerized database, create forms and reports from the data, sort and retrieve data and modify and delete data.
Garbage in, garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input .

Valuable information should have the following characteristics:

1.Accurate
2.Verifiable
3.Timely
4.Organized
5.Accessible
6.Useful
7.Cost-effective

 

The Hierarchy Of Data:

1.Character
2.Field
3.Records
4.Files

File maintenance refers to the procedure of adding, modifying and deleting records.(Adding , deleting, modify records )
Validation compares data with a set of rules or values to find out if the data is correct.
Database validation is required when databases get corrupted to check for corruption.

Types of validity checks:
1. Alphabetic/Numeric check
2. Range check
3. Consistency check
4. Completeness check
5. Digit check

File processing versus Database approach.
File processing system:
1.Each department has its own set of files.
2. Have data redundancy.
3. Isolate data.

Database approach:
1. Programs and users share data.
2. Reduce data redundancy.
3. Improve data integrity.
4. Share data.
5. Allow easier access.
6. Reduce development time.
7. More vulnerable.

Database Management Systems
1. Data dictionary- contains data about each file in the database and each field in those lines.
2. Query language- consist of simple, english like statements that allow users to specify the data to display, print or store.
3. Query by example (QBE)- provide a graphical user interface to assist users with retrieving data.
4. Form- window on the screen that provide areas for entering or modifying data in a database.
5. Report generator- allows users to design a report on the screen, retrieve data into the report design and then display or print the report.

Relational,Object-Oriented,and Multidimensional Databases

Data model consists of rules and standard that define how the database organizes data. 

Relational database stores data in tables that consists of rows and columns. 
-Each row has a primary key. 
-Each columns has a unique name. 
-A relationship is a link within the data. 

Structured Query Language (SQL) is a query language that allows users to manage,update,and retrieve data. 
Object-oriented database (OODB) stores data in object. 
Examples of applications appropriate for an object-oriented database include: 
1.Multimedia database 
2.Groupware database 
3.Computer-aided design database 
4.Hypertext database 

Multidimensional database can store data in more than two dimensional of data. 
sometimes known as a hypercube 
Can consolidate data much faster than a relational database 
Data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.

Chapter 8 - Type of Storage

Storage is frequently used to mean the devices and data connected to the computer through input/output operations A Storage is any computing hardware that is used for storing, porting and extracting data files and objects. It can hold and store information both temporarily and permanently, and can be internal or external to a computer, server or any similar computing device.
Storage holds data,instructions,and information for future use.A storage medium is the physical material on which a computer keeps data,instruction,and information.

Capacity is the number of bytes a storage medium can hold.


A Storage device is the computer hardware that records and/or retrieves items to and from storage media. 

Reading  is the process of transferring items from a storage medium into memory. 
Writing  is the process of transferring items from memory to a storage medium. 

Access time measures by the amount of time it takes a storage device to locate an item on a storage medium and the time required to deliver an item from memory to the processor.


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Hard disks

A hard disk drive (sometimes abbreviated as HDD ) is a non-volatile memory hardware device that permanently stores and retrieves information.

A hard disk contains one or more inflexible,circular platters that use magnetic particles to store data,instructions, and information.
Hard disks can store data using longitudinal recording or perpendicular recording.
Characteristics of a hard disk include:
1.Capacity
2.Platters
3.Read/Write heads
4.Cylinders
5.Sectors and tracks
6.Revolutions per Minute
7.Transfer Rate
8.Access Time 

Formatting is the process of diving the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.

How a Hard Disks Works

 

1st :  The circuit board controls the movement of the head actuator and a small motor.

2nd : Small motor will spins the platters while the computer is running.

3rd:  When software requests a disk access,the read/write heads determine the current or new location of the data.

4th : The head actuator positions the read/write head arms over the correct location on the platters to read or write the data.

 

How Disk Cache Works

 

1st : A special-purpose chip on the hard disk, called a controller,receives a request for data,instructions,or information from the processor.

2nd : The controller first checks disk cache for the requested item.

3rd : If the controller does not find the requested item in disk cache, it locates the requested item on the hard disk's platters.

4th : The controller transfers the requested item to the processor. 

RAID (Redundant array of independent disks) is a group of two or more integrated hard disks.

Network attached storage (NAS) device e is a server connected to a network with the sole purpose of providing storage.

External hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly.

Removable hard disk is a hard disk that you insert and remove from a drive.

Internal and external hard disks are available in miniature sizes(miniature hard disks).

Disk controller consists of a special-purpose chip and electronic circuits that control the transfer of data,instructions ,and information from a disk to and from the system bus and other components of the computer. SATA , EIDE, SCSI ,SAS.


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Flash Memory Storage

Flash memory chips are a type of solid-state media and contain no moving parts.
Solid state drives (SSD) have several advantages over magnetic hard disks

  1.Faster access time

  2.Faster transfer rates

  3.Last longer

  4.Generate less heat and consume less power

 

 Types of flash memory storage:
1_ Memory card- removable flash memory device that can be inserted and removed from a slot in computer, mobile devices and card reader/writer.
Example :
  1.Compact Flash (CF)
  2.Secure Digital (SD)
  3.Secure Digital High Capacity (SDHC)
  4.Micro SD
  5.Micro SDHC
  6.Picture Card ( GRAPHIC CARD ?? )
  7.Memory Stick
  8.Memory Stick Micro (M2)
 

2_ USB flash drive- plug into USB port on a computer or mobile device.

3_Express card module-removable device that fits in express card slot.

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Cloud Storage 

An Internet service that provides storage to computer users.Users subscribe to cloud storage for a variety of reasons:

1.Access files from any computer
2.Store large files instantaneously
3.Allow others to access their files
4.View time-critical data and images immediately
5.Store offsite backups
6.Provide data center functions
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Optical Discs

An Optical Disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.Typically store software, data, digital photos, movies, and music.
How a Laser Reads Data on an Optical Disc

1.A laser diode shines a light beam toward the disc.

2.If light strikes a pit, it scatters.If light strikes a land, it is reflected back toward the laser diode.

3.Reflected light is deflected to a light-sensing diode,which sends a digital signal of 1 to the computer.Absence of reflected light is read as a digital signal of 0.

 

Tape- magnetically coated ribbon of plastic capable of storing large amount of data and informations. Require tape drive to read and write data and information.

Magnetic stripe card- contains magnetic stripe that stores information.

Smart card- stores data on thin microprocessor embedded in the card.

Microfilm and microfiche- store microscopic images of documents on a roll or sheet film.

Enterprise storage- uses special hardware to store huge volume of data and information for large businesses.